Extension-ladder



(No Model.)

V. HOLMQVIST. EXTENSION LADDER.

No. 427,992. Patented May 13, 1890.

' INVENTO UNITED STATES PATENT OFFICE.

VICTOR HOIJMQVIST, OF CHICAGO, ILLINOIS.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent No. 427,992, dated May 13,1890.

Application filed December 12, 1889. Serial N0.3S3,523. (N0 model.)

To all whom it may concern.-

Be it known that I, VICTOR Honnovrsr, a subject of the King of Swedenand Norway, but having declared my intention of becoming a citizen ofthe United States, residing at Chicago, in the county of Cook and Stateof Illinois, have invented a certain new and useful Improvement inExtension-Ladders, of which the following is a specification.

This invention relates to that type of extension-ladders in which asupplementary section is made vertically adjustable on a main or lowersection, and is secured at the desired adjustment by holdinghooks uponthe one engaging the proper round of the other; and the presentimprovement has for its object to provide an improved construction forsuch type of ladders embodying the features of a cheap and durable meansfor operatingthe holding-hooks of the upperlad der-section, a simple andeffective manner of attaching such hooks in place, a strong and durableconstruction of roller-bracket at the top of the main ladder-section forguiding and confining the movable ladder-section in its movement on themain ladder-section, and a frictionless bearing-s11 rface at the top ofthe movable section,so that the movement of the same up the side of awall, &c., in the adj ustment of theladder-sections, can be easily andreadily effect-ed. I attain such object by the construction andarrangement of parts illustrated in the accompanying drawings, inwhicl1- Figure 1 is a detail vertical section of an extension-ladderembodying my present i11- vention; Fig. 2, a detail cross-section of thesame, illustrating my improved form of rollerbearing; Fig. 3, a detailelevationillustrating the arrangement of holder-hooks for the movableladder-section; Fig. 4, an elevation, partly sectionized, of the upperend of the movable ladder-section, illustrating my -improvedconstruction of bearing-roller for the ladder-top; and Fig. 5, a detailsection at line so as, Fig. 1.

Similar "letters of reference indicate like parts in the several views.

Referring to the drawings, the ladder consists of an upper and lowersection composed of side bars or stiles A B,connected together in theusual manner by cross-rods or rounds C D, the side bars or stiles A ofthe upper section being arranged to slide upon the rounds of the lowerladder-section, as shown, and are held in contact with the same by meansof roller-brackets E, secured to the upper ends of the side bars orstiles B of the lower ladder-section. In the present invention thisroller-bracket consists of a plate E, bent at one end to embrace theunder edge of the stile and at its other end having alaterally-projecting stirrup or U-shaped plate E, riveted in place and.extending parallel with the stile to form a housing for theanti-friction roller E the pivot-pin of which passes through saidstirrup and the upper end of the plate E, as illustrated in Figs. 1 and2. The bracketplate E is screwed to the inside face of its, stile B, asshown, and its portion projecting above the style is strengthened by aninclined brace-plate E extending to the outside of the stile, asillustrated in Fig. 2. In the present invention the bracket-plate E isalso utilized to tie the top of the lower ladder-section together bybeing set in a saw-cut or gain 01 near each end of the top round D, asshown in Figs. 1 and 5.

The holding-hook for the movable laddersection consists of counterparthooks F F, united together by a cross rod or stem F, which passesthrough the stile A, to form a journal or pivot for the hooks, the hooksF and the uniting-rod F being formed integrally by bending a rod of ironinto the required shape. In the present invention the holderhooks F areinserted into place in the lower ends of the stiles A in the followingmanner: A longitudinal saw-slit a is first made in the lower end of thestile. The parts are then pressed together and a cross orifice or holefor the pivot-rod F is then bored, af ter which the parts are sprungapart for the introduction into place of the holder-hook, after whichthe parts are brought together and secured by cross rivets or screws f,as clearly illustrated in Figs. 1 and 3.

To attain an easy and convenient manipulation of the holder-hooks F, Iemploy the following improved construction: G is a lever pivoted at g tothe inside of the stile and extending along the same, its lower endbeing slotted, so as to engage around the cross-rod F of theholder-hooks; and such slot g is of an elongated form so as to admit ofthe proper movement of the lower end of the lever Gon such cross-rod. Ashort distance above the slot g are lugs on the side of the lever G,between which the shank of the holder-hook is received, so that amovement of said lever will impart a movement in a reverse direction'tothe hooks, and by this means, owing to the ready accessibility to thelower end g of theleverof theth u mb of theoperator, the ready operationof the holder-hook is easily effected. In the upward movement. of theladder-section the movement of the holder-hooks will be automatic, thelever G being provided with an inclined portion G, which rides over therounds of the lower ladder-section to move the hooks up out of the pathof the same. At top the movable section is provided with abearing-roller ll, extending the width of the ladder, and provided withjournalnns 72,that turn in oriliees 71 in the upper ends of the stilesA, as shown, the corners of the stiles being beveled oil, as shown inFig. 1, to admit of the proper action of the bearinga'oll ll at alltimes.

By the above provision of the bearingroller extending the width of theladder the following advantages are attained over the ordinary rollerarranged in or at the sides of the ladder-stilesz first, it furnishesperfect means for adjusting the ladder up the side of a post or columnor the corner of a wall; second, it affords wide bearing-surface, so asnot to be affected by irregular depressions, &c., in the wall, &c.,.uponwhich an adjustment is effected.

Having thus fully described my said invention, what I claim as new, anddesire to secure by Letters Patent, is

1. The combination, with the stationary and movable sections of; anextension-ladder, of the roller-bracket plate E, secured to the insideof the stile 13, the laterally-projecting U-shaped or stirrup plat-e E,secured to the plate E, and roller E journaled in the same, asdescribed, and for the purpose set forth.

2-. The combination, with the stationary and movable sections of anextension-ladder, of the roller-bracket plate E, secured to the insideof the stile B, the laterally-projecting U-shaped or stirrup plate It,secured to the plate E, the roller E jonrnaled in the same, and theinclined brace-plate E, secured to the plate E and extending to theoutside of the stile, as and for the purpose set forth.

3. The combination, with the stationary and movable sections of anextension-ladder, of the bracket-platc E, secured to the inside of thestile I and engaging in a gain (I in the top round of the lowerladder-section, as described, and. for the purpose set forth.

4.. The combination, with the stationary and movable sections of anextension-ladder, of the double holder-hooks I1, journaled in the stileA, and the pivoted lever G, formed with lugs f, and a transverseelongated slot g, as desm-ibed, and for the purpose set forth.

5. The combination, with the stationary and movable sections of anextension-ladder, of the. double holder-hooks l jonrnaled in the stileA, and the pivoted lever G, formed with an inclined portion G,counterpart lugs 1 and transversely-extending elongated slot g, asdescribed, and for the purpose set forth.

6. In an extension-ladder, the combination of the holder-hooks F F,formed double and connected together by a cross rod or stem F, with thestile A, formed with a longitudinal slit 1/, a pivot-hole for the rod orstem 11", and the confining screws or rivets f, as described, and forthe purpose set forth.

7. The combination, in an extension-ladder, of the movable laddersectionhaving the upper ends of its stiles beveled oil, with the bearing-rollerII, journaled in said upper ends and extending the width of theladdersection, as described,am.l for the purpose set forth.

In testimony whereof; witness my hand this 7th day of December, 1889.

VICTOR I-IOLMQVIST.

In presence of-- ROBEH'J. B URNS, (JEo. II'. ARTHUR.

